ODE No. 1066

\[ y''(x)+\tan (x) y'(x)+y(x) \cos ^2(x)=0 \]

✓ Mathematica : cpu = 0.0266617 (sec), leaf count = 18

DSolve[Cos[x]^2*y[x] + Tan[x]*Derivative[1][y][x] + Derivative[2][y][x] == 0,y[x],x]

\[\{\{y(x)\to c_2 \sin (\sin (x))+c_1 \cos (\sin (x))\}\}\]

✓ Maple : cpu = 0.126 (sec), leaf count = 15

dsolve(diff(diff(y(x),x),x)+diff(y(x),x)*tan(x)+y(x)*cos(x)^2=0,y(x))

\[y \left (x \right ) = c_{1} \sin \left (\sin \left (x \right )\right )+c_{2} \cos \left (\sin \left (x \right )\right )\]